Change unit dates/lengths more easily

Sometimes I need to adjust the dates of a unit just a little. In the unit planner view, you can push a whole unit forward OR pull the end of it to become longer, but you can't pull the front of it to make it shorter. If you try to shorten it by pulling the end of the previous unit to make that one longer, it bumps the next unit out completely. It would be nice if the "pulling" part was more natural OR there was a place to type in the unit's dates.